Small denier stuffer crimper and method

ABSTRACT

A stuffer crimper for small denier yarns having feed rolls of from 1.0 to 1.26 inches in diameter and an angle between the radii to the bite and to the wiping edge of the saddle in the plane of the end of the traverse of 38* to 29*, respectively. This dimension if achieved by providing a yarn traverse across the bite of the feed rolls that leaves a 0.05-inch clearance from the edges.

United States Patent Torello-Viera [15] 3,685,109 1 Aug. 22, 1972 [54] SMALL DENIER STUFFER CRIMPER AND METHOD [72] Inventor: Eugene Torello-Viera, Claymont,

Del.

[73] Assignee: Joseph Bancroft & Sons C0.,

Wilmington, Del.

[22] Filed: June 11, 1970 [21 Appl. No.: 45,307

[52] US. Cl. ..28/1.6, 28/1.7, 28/7214 [51] Int. Cl. ..D02g l/l2 [58] Field of Search ..28/1.6, 1.7, 72.14

[56] References Cited UNITED STATES PATENTS 2,997,747 8/1961 Russo et a1. ..28/1.6

3,000,060 9/ 1961 Shattuck et al ..28/ l .6 3,353,767 11/1967 Hodges et al. ..28/1 .6 X 3,120,692 2/1964 Crawford et a1 ..28/72.14

Primary Exarniner-Louis K. Rimrodt Attorney-Birch, Swindler, McKie and Beckett [57] ABSTRACT A stuffer crimper for small denier yarns having feed rolls of from 1.0 to 1.26 inches in diameter and an angle between the radii to the bite and to the wiping edge of the saddle in the plane of the end of the traverse of 38 to 29, respectively. This dimension if achieved by providing a yarn traverse across the bite of the feed rolls that leaves a 0.05-inch clearance from the edges.

5 Claims, 4 Drawing Figures PATENTEDAUBZZ I912 3.685; 109

FIG. I

INVENTOR. EUGENE TORELLO-VIERA ATTORNEY SMALL DENIER STUFFER CRIMPER AND METHOD This invention relates to stufier crimpers of the type having feed rolls and a traversing guide for guiding yarn or filaments for crimping into the bite of such rolls.

An object is to provide a stuffer crimper adapted for use with small denier multifilament yarns which is designed and arranged to prevent or minimize breakage of the filaments in the zone between the bite and the crimping tube saddle.

Another object is to prevent the breakage of filaments by being pinched between the feed rolls and the adjacent edge of the saddle.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

In accordance with the present invention it has been found that filament bundles, particularly when in the untwisted state or having a low twist such as a producers twist of less than one turn per inch, flower out in all directions adjacent the bite of the feed rolls as they are folded over and .become crimped and the outside filaments tend to become pinched between the feed roll and the saddle with consequent tendency towards looping and breakage. This occurs particularly at the limits of the traverse movement where such filaments are close to the edge of the feed roll and to the wiping surface of the saddle.

This tendency depends upon the size of the bundle,

the size of the filaments, the number of filaments in the.

bundle, the degree of twist, and the spacing at the limit of the traverse from the end of the feed roll and from the wiping surface of the saddle. By eliminating this tendency it is possible to increase the bulk level of the yarn, particularly in the case of filaments of low elongation at break which are easily broken. Thus the back pressure on the filaments in the crimping zone can be increased without causing the filaments to become pinched under the wiping surface.

In small denier crimpers for example, crimpers adapted for crimping yarns of the order of from 40 to 200 denier, these clearances are critical factors and must be maintained within certain limits in order to prevent pinching and entangling of the filaments. These limits are set forth in the following description.

The nature of the invention will be better understood from the following description, taken in connection with the accompanying drawing in which a specific embodiment has been set forth for purposes of illustration.

In the drawing:

FIG. 1 is a vertical section through a stuffer crimper embodying the invention;

FIG. 2 is a broken side elevation of a portion of the stuffer crimper of FIG. 1;

FIG. 3 is a section taken on the line 3-3 of FIG. 2 but on a much larger scale, and

FIG. 4 is a section taken on the line 4-4 of FIG. 3 showing the spacing between the bite and the wiping edge of the saddle.

Referring to the drawing more in detail the crimper is shown as having a crimping and setting tube forming the crimping and setting chamber and secured in a heater block 11 having a plurality of heating elements 12 disposed therein.

A pair of feed rolls l4 and 15 is disposed to feed a bundle 16 of filaments for crimping into the tube 10. A

traverse roll 17 having a traversing guide 18 is disposed to guide the filament bundle 16 into the bite of the feed rolls l4 and 15 and to traverse the bundle laterally along the bite between extreme positions indicated at 19 and 20. The distance between the points 19 and 20 and the adjacent edges of the feed rolls is designated as 22.

At its lower end, the tube 10 communicates with a saddle 30 having a bore corresponding to or slightly less than that of the tube 10 and having its lower end milled out to seat around the bite and having flanks extending over the end surfaces of the rolls 14 and 15 and having a running clearance therewith.

The crimped yarn within the tube 10 forms a core 32 from the upper end of which the yarn is withdrawn through an opening 33 in a tube cap 34.

A sensing device in the form of a slug 35 rests on the top of the core 32 in the tube 10 to rise and fall therewith. The sensing device 35 includes elements 37 extending outwardly through slots 38 in the tube 10. A microswitch 40 is carried by a bracket 41 which is adjustably secured to the tube 10 and has an actuating arm 42 which extends around the tube 10 and rests upon and is actuated by the outwardly protruding elements 37 as they rise and fall. The microswitch is connected to control the rate of the feed rolls or of the delivery rolls or winder, not shown, in a sense to maintain the top of the core of crimped yarn at a substantially constant level in the tube 10.

Referring to FIG. 4 which is a transverse section taken at the point 19 at the end of the throw of the yarn, the lower end of the saddle 30, referred to as the wiping edge for convenience although a running clearance is provided between the edge'of the saddle and the surface of the feed roll, is designated as 24. The angle between the radii to the bite and to the point 24 is designated as the angle A.

The crimper in accordance with this invention is specifically designed for use with filament bundles of small denier, such as nylon or polyester bundles or yarns of from 40 to 200 denier which may be composed of a large number of individual filaments and may have a degree of twist of less than one turn per inch. It is especially suited for the crimping of polyester or other yarns having low filament elongation at break.

In the above crimper the traverse roll 17 has a throw adapted to leave a spacing 22 between the filaments at each end of the throw and the corresponding edges of the rolls at the bite of at least 0.05 inch.

As a specific example, in order to make the improved crimped yarn of this invention with a crimper having 1.26 inch diameter feed rolls, the minimum inside diameter of the crimping tube should be 0.27 inch. The feed rolls must have a width sufficient to span the inside diameter of the tube yet have a running clearance with the wiping edge and flanks of the saddle, and the extreme traverse of the yarn should be approximately 0.05 inch from the edge of the feed rolls. This provides for an angle A of approximately 29 which is the minimum angle necessary to provide the spacing between the bite and the wiping edge of the saddle which is required to avoid pinching of the yarn between the surface of the feed rolls and the wiping edge of the saddle. In the case of 1.0 inch diameter feed rolls in a crimper which otherwise has the same dimensions, the minimum angle A becomes approximately 38.

It has been found that in a crimper with these dimensions the filaments do not become pinched between the ends of the feed rolls and the saddle 30.

A further feature of the invention is the redistribution of the factors that contribute to the bulk level of 40 to 200 denier continuous multifilament nylon or polyester crimped yarn of less than one turn of twist per inch which results in an improved yarn characterized by fewer faults per yard at any given bulk level than in such previously known stuffer crimped yarns. This is primarily the result of the clearance of at least 0.05 inch between the yarn at the ends of the throw and the ends of the feed rolls combined with the saddle diameter of at least 0.27 inch as explained above which causes the core of crimped yarn to be less tightly packed against the chamber walls, but still supportable thereby, and thus advance along the chamber with less friction than if the above clearances and diameters were of lesser value. Further, these values provide for a reduced wall to yarn friction ratio in and of itself compared to previously known apparatus. With this reduced amount of friction, the yarn folds over and crimps at longer intervals which results in longer leg lengths in the crimped filaments.

It should be noted that, although the yarn is less tightly packed in the chamber, the dwell time of the yarn in the chamber due to the increased diameter is increased slightly so that the crimp imparted to the yarn is set more permanently for any given length of chamber. Consequently, at any given bulk level the yarn of this invention is characterized by longer leg lengths and tighter crimp angles than previously known stuffer crimped yarn of similar deniers.

It should still further be observed that, in achieving a yarn with a bulk level in accordance with this invention which is the same as the bulk level made by previously known apparatus, the backweight exerted on the end of the core of crimped yarn in the chamber constitutes at least 33 percent and 45 percent factors in the total bulk level of such stuffer crimped polyester and nylon yarns, respectively. This was determined to be the case in trials conducted on commercially available nylon and polyester yarns having less than one turn of twist per inch in a denier range of from 40 to 200 in a crimping apparatus of the above mentioned dimensions and in which the length of the chamber was at least 20 times its diameter in bulk level ranges of percent 28 percent and 18 percent 35 percent on polyester and nylon yarns respectively.

The trials consisted of measuring the bulk level of the yarns when crimped without any backweight and comparing them to similar yarns crimped with a backweight calculated to give the bulk levels in the ranges aforementioned. The bulk levels were determined by winding a predetermined number of yards of the crimped yarn on a 54 inch skein reel, removing the wound skein from the reel, suspending the skein on a rod in an oven under a 1% oz. tension for 5 minutes, removing the yarn from the oven and measuring the percent shrinkage in length of the skein. For example, on 40 denier yarns of polyester and nylon, 185 yards were wound into skeins and put into ovens for 5 minutes under the onehalf oz. tension. On 70 denier yarns of polyester and nylon, 130 yards were wound into skeins, and on 150 denier nylon and polyester, 125 yards were wound. The ovens were set at 250 F for nylon and 220 F for polyester. The tables below show the bulk levels obtained on denier polyester and nylon yarns under varying amounts of backweight. Similar results were obtained on other yarns in the denier ranges of the invention.

TABLE 1 70 denier, 34 filament nylon 66 Backweight Bulk Level 0 grams 9.4 4 grams 18.5 l8 grams 27.2

TABLE 2 7O denier, 34 filament Dacron" polyester T26 Backweight Bulk Level 0 grams 10.4 4 grams [5.5

Accordingly it can be seen that the inherent wall fric' tion factor built into the apparatus is reduced and replaced by a more controllable backweight factor thereby enabling the apparatus of this invention to produce a wider range of bulk levels in any given denier of yarn at any given speed of yarn feed than in previously known apparatus with fewer faults as explained below.

It has been further found that because of the prevention of pinching of the filaments between the surfaces of the feed rolls and the wiping edges of the saddle and the reduction in wall friction, yarns crimped in this apparatus have substantially fewer faults per yard than similar yarns crimped in previously known apparatus. A fault is defined as a broken filament or a filament having an undesirable loop, kink or being disarranged from the yarn bundle. The test for determining faults involves running yarn at 6 yards per minute for 20 minutes yards) under a 4-5 gram tension. Loops, kinks or disarranged filaments are considered independent faults when they are spaced further from each other than their individual length along the yarn. A filament was considered a kink, loop or disarranged filament when it stuck out from the yarn bundle more than the thickness of the yarn bundle itself.

For example, a 40 denier, l3 filament nylon yarn having a twist of less than one turn per inch crimped as above was found to have an average of not over 0.4 faults per yard as compared with 2.4 faults per yard in such previously known stuffer crimped yarn.

What is claimed is:

l. A stuffer crimper for use with filament bundles of 40 to 200 denier comprising a member forming a crimping and setting chamber, a pair of feed rolls having end surfaces and forming a bite disposed to feed a' filament yarn into one end of said chamber to be folded over and crimped therein against a core of previously crimped yarn, said crimping chamber including a saddle. spanning the bite of said feed rolls and having flanks extending over the end surfaces thereof with running clearance between the flanks and said end surfaces, and a traverse guide driven to traverse the yarn laterally across approximately the full bite of said rolls as it is fed thereto for crimping, said traverse guide having a throw less than the inside diameter of the saddle and related to the width of said feed rolls to provide a minimum clearance of 0.05 inch between the filaments at the ends of the throw and the corresponding ends of the feed rolls at the bite whereby the crimped yarns is less tightly packed against the chamber walls and thus advances along said chamber with less friction.

2. A stuffer crimper as set forth in claim 1 in which the diameters of said feed rolls are in the range of 1.0 to 1.26 inches and the angle between the feed roll radii to the bite and to the wiping edge of the saddle in the plane of the end of the traverse is from 38 to 29, respectively, whereby the filaments are prevented from becoming pinched between said rolls and said saddle.

3. A ,stuffer crimper as set forth in claim I in which.

the saddle has an internal diameter of at least 0.27 inch.

4. The method of producing crimped 40 to 200 denier continuous multi-filament nylon yarn having less than one turn of twist per inch and having bulk levels of from 18 percent to 35 percent measured by winding a predetermined length of crimped yarn on a skein reel, removing the wound skein from the reel, suspending the skein in a heated atmosphere under predetermined tension for a predetermined time, removing the yarn from the heated atmosphere and measuring the percentage shrink in length of the skein, such crimped yarn being produced in a stuffer crimper having feed rolls and a chamber whose length is at least twenty times its width which comprises;

feeding said yarn into said chamber with a traversing throw across approximately the full bite of the feed rolls but less than the inside diameter of said chamber and related to the width of the feed rolls to provide a minimum clearance of 0.05 inch between the filaments at the ends of the throw and the corresponding ends of the feed rolls at their bite whereby the crimped yarn is less tightly packed against the chamber walls and thus advances along said chamber with less friction; and opposing the advance of the yarn by a backweight which contributes 45 percent to percent to the total bulk level of the crimped yarn as measured with respect to the bulk level obtained without backweight applied to oppose advance of the yarn. 5. The method of producing crimped 40 to 200 denier continuous multi-filament polyester yarn having less than one turn of twist per inch and having bulk levels of from l0 percent to 28 percent measured by winding a predetermined length of crimped yarn on a skein reel, removing the wound skein from the reel, suspending the skein in a heated atmosphere under predetermined tension for a predetermined time, removing the yarn from the heated atmosphere and measuring the'percentage shrink in length of the skein, such crimped yarn being produced in a stuffer crimper having feed rolls and a chamber whose length is at least twenty times its width which comprises;

feeding said yarn into said chamber with a traversing throw across approximately the full bite of the feed rolls but less than the inside diameter of said chamber and related to the width-of the feed rolls to provide a minimum clearance of 0.05 inch trtaissofirrgas ti trt ieza isiiaiei bite whereby the crimped yarn is less tightly packed against the chamber walls and thus advances along said chamber with less friction; and opposing the advance of the yarn by a backweight which contributes 30 percent to 50 percent to the total bulk level of the crimped yarn asmeasured with respect to the bulk level obtained without backweight applied to oppose advance of the yarn. 

1. A stuffer crimper for use with filament bundles of 40 to 200 denier comprising a member forming a crimping and setting chamber, a pair of feed rolls having end surfaces and forming a bite disposed to feed a filament yarn into one end of said chamber to be folded over and crimped therein against a core of previously crimped yarn, said crimping chamber including a saddle spanning the bite of said feed rolls and having flanks extending over the end surfaces thereof with running clearance between the flanks and said end surfaces, and a traverse guide driven to traverse the yarn laterally across approximately the full bite of said rolls as it is fed thereto for crimping, said traverse guide having a throw less than the inside diameter of the saddle and related to the width of said feed rolls to provide a minimum clearance of 0.05 inch between the filaments at the ends of the throw and the corresponding ends of the feed rolls at the bite whereby the crimped yarn is less tightly packed against the chamber walls and thus advances along said chamber with less friction.
 2. A stuffer crimper as set forth in claim 1 in which the diameters of said feed rolls are in the range of 1.0 to 1.26 inches and the angle between the feed roll radii to the bite and to the wiping edge of the saddle in the plane of the end of the traverse is from 38 to 29*, respectively, whereby the filaments are prevented from becoming pinched between said rolls and said saddle.
 3. A stuffer crimper as set forth in claim 1 in which the saddle has an internal diameter of at least .27 inch.
 4. The method of producing crimped 40 to 200 denier continuous multi-filament nylon yarn having less than one turn of twist per inch and having bulk levels of from 18 percent to 35 percent measured by winding a predetermined length of crimped yarn on a skein reel, removing the wound skein from the reel, suspending the skein in a heated atmosphere under predetermined tension for a predetermined time, removing the yarn from the heated atmosphere and measuring the percentage shrink in length of the skein, such crimped yarn being produced in a stuffer crimper having feed rolls and a chamber whose length is at least twenty times its width which comprises; feeding said yarn into said chamber with a traversing throw across approximately tHe full bite of the feed rolls but less than the inside diameter of said chamber and related to the width of the feed rolls to provide a minimum clearance of .05 inch between the filaments at the ends of the throw and the corresponding ends of the feed rolls at their bite whereby the crimped yarn is less tightly packed against the chamber walls and thus advances along said chamber with less friction; and opposing the advance of the yarn by a backweight which contributes 45 percent to 60 percent to the total bulk level of the crimped yarn as measured with respect to the bulk level obtained without backweight applied to oppose advance of the yarn.
 5. The method of producing crimped 40 to 200 denier continuous multi-filament polyester yarn having less than one turn of twist per inch and having bulk levels of from 10 percent to 28 percent measured by winding a predetermined length of crimped yarn on a skein reel, removing the wound skein from the reel, suspending the skein in a heated atmosphere under predetermined tension for a predetermined time, removing the yarn from the heated atmosphere and measuring the percentage shrink in length of the skein, such crimped yarn being produced in a stuffer crimper having feed rolls and a chamber whose length is at least twenty times its width which comprises; feeding said yarn into said chamber with a traversing throw across approximately the full bite of the feed rolls but less than the inside diameter of said chamber and related to the width of the feed rolls to provide a minimum clearance of .05 inch between the filaments at the ends of the throw and the corresponding ends of the feed rolls at their bite whereby the crimped yarn is less tightly packed against the chamber walls and thus advances along said chamber with less friction; and opposing the advance of the yarn by a backweight which contributes 30 percent to 50 percent to the total bulk level of the crimped yarn as measured with respect to the bulk level obtained without backweight applied to oppose advance of the yarn. 